Antibodies are coded by three families of genes--lambda, Kappa and Eta. Each family is generally multigenic. The multigenic antibody families display unusual evolutionary features which suggest the presence of novel evolutionary mechanisms as well as unusual genetic features which suggest that gene translocation plays a role in the differentiation of the antibody-producing cell. The genetic basis for antibody diversity, evolution, and expression will be studied through the comparative amino acid sequence analysis of immunoglobulins derived from selected vertebrates--primarily the NZB mouse, the rabbit and the shark. The accumulation of large amounts of data should permit one to discern sequence patterns which will place important constraints on the mechanisms for information storage, expression and evolution in the immune system. Other multigene systems (e.g., histones and ribosomal genes) also display unusual evolution features similar to those seen in antibodies. Thus the immune system with its readily accessible gene products may serve as a general model for elucidating genetic and evolutionary mechanisms in other less accessible multigenic systems. I would like to find and explore some of these less accessible multigene systems. BIBLIOGRAPHIC REFERENCES: J. Silver and L. Hood. Structure and evolution of transplantation antigens: partial amino acid sequences of H-2K and H-2D alloantigens. Proc. Nat. Acad. Sci., USA 73, 599-603, 1976. J. Silver and L. Hood. Genetic and evolutionary implications of the partial amino acid sequences of H-2K and H-2D alloantigens. In: The Role of Products of the Histocompatibility Gene Complex in Immune Responses. D. H. Katz and B. Benacerraf, editors. Academic Press, Inc., New York. 1976. pp. 677-689.